add mp4

Author: LarsKoelpin

package-lock.json

@@ -1,12 +1,13 @@
 {
   "name": "magic-bytes.js",
-  "version": "1.0.8",
+  "version": "1.0.9",
   "main": "./dist/index.js",
   "module": "./dist/index.js",
   "types": "./dist/index.d.ts",
   "scripts": {
     "prettier": "prettier --write \"{src,__{tests,mocks}__}/**/*.{tsx,ts}\"",
     "gen-tree": "ts-node ./src/create-snapshot.ts",
+    "pre-test": "jest --clear-cache",
     "test": "jest",
     "build": "tsc"
   },
@@ -37,11 +38,11 @@
     "@types/jest": "^27.0.1",
     "@types/node": "^16.6.2",
     "jest": "^27.0.6",
-    "prettier": "^1.19.1",
+    "prettier": "^2.6.1",
     "regenerator-runtime": "^0.11.1",
     "ts-jest": "^27.0.5",
     "ts-node": "^10.2.1",
-    "typescript": "^4.3.5"
-  },
-  "dependencies": {}
+    "typescript": "^4.3.5",
+    "prettier-plugin-organize-imports": "^2.3.4"
+  }
 }

package.json

@@ -1,10 +1,10 @@
+import * as fs from "fs";
 import {
+  filetypeextension,
   filetypeinfo,
-  filetypename,
   filetypemime,
-  filetypeextension
+  filetypename,
 } from "./index";
-import * as fs from "fs";
 
 describe("Tests the public API", () => {
   it("detects tar with offset", () => {
@@ -14,6 +14,13 @@ describe("Tests the public API", () => {
     expect(filetypeinfo(bytes)[0].typename).toBe("tar");
   });
 
+  it("detects mp4", () => {
+    const buffer = fs.readFileSync(require.resolve("./testfiles/a.mp4"));
+    const bytes = Array.prototype.slice.call(buffer, 0);
+    expect(filetypeinfo(bytes)).toHaveLength(1);
+    expect(filetypeinfo(bytes)[0].typename).toBe("mp4");
+  });
+
   it("filetypeinfo", () => {
     const bytes = [0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a];
     expect(filetypeinfo(bytes)).toHaveLength(1);

src/index.spec.ts

@@ -1,6 +1,8 @@
-import patternTree from "./pattern-tree.snapshot";
-import { GuessedFile, Node, Tree } from "./model/tree";
+import createTree from "./model/pattern-tree";
 import { fromHex, toHex } from "./model/toHex";
+import { GuessedFile, Node, Tree } from "./model/tree";
+
+const patternTree = createTree();
 
 export const filetypeinfo = (
   bytes: number[] | Uint8Array | Uint8ClampedArray
@@ -13,7 +15,6 @@ export const filetypeinfo = (
       continue;
     }
     const node: Node = (patternTree as any).offset[k];
-
     const guessed = walkTree(offset, bytes, node);
     if (guessed.length > 0) {
       return guessed;